Fluxless wafer bonding with Sn-rich Sn-Au dual-layer structure
Fluxless wafer bonding with Sn-rich Sn-Au dual-layer structure
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DOI：
10.1016/j.msea.2005.11.009
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发表时间：
2006-02
期刊：
影响因子：
6.4
通讯作者：
Jongsung Kim;Chin C. Lee
中科院分区：
文献类型：
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作者：
Jongsung Kim;Chin C. Lee
我们报告了粘合两个 2 英寸的初步结果。采用电镀工艺生产的富锡Sn-Au双层结构的硅片。粘合过程中不使用助焊剂。与富Au Au80Sn20共晶合金相比，由于锡氧化，使用富Sn Sn-Au合金更难以实现无助熔剂特性。在最初的努力中，生产了两个样品。由此产生的富锡焊点层厚度约为 30μm，在整个 2 英寸焊点上非常均匀。样本。使用扫描声学显微镜 (C-SAM) 和 X 射线显微成像技术检查接头的质量。这两种技术的图像表明接头质量很高。在这两个样品中，较好的一个显示出近乎完美的接缝，仅有 2% 的可能空隙区域。这一初步成功表明，确实可以通过高质量的薄金属接头将整个晶圆粘合在一起。这种无助焊剂技术可以扩展到粘合不同材料的晶圆，以用于新器件和封装应用。使用高熔化温度的金属合金层也是可能的并且正在考虑中。
We report our initial result of bonding two 2in. silicon wafers using Sn-rich Sn–Au dual-layer structure that is produced by electroplating process. No flux is used in the bonding process. Comparing to Au-rich Au80Sn20 eutectic alloy, it is more difficult to achieve fluxless feature using Sn-rich Sn–Au alloys due to tin oxidation. In this initial effort, two samples are produced. The resulting Sn-rich solder joint layer, about 30μm in thickness, is very uniform over the entire 2-in. sample. The quality of the joint is examined using scanning acoustic microscope (C-SAM) and X-ray micro-imaging technique. Images of these two techniques indicate that the joints are of high quality. Of the two samples, the better one shows nearly perfect joint with only 2% of possible void area. This initial success shows that it is indeed possible to bond entire wafers together with a thin metallic joint of high quality. This fluxless technique can be extended to bonding wafers of different materials for new device and packaging applications. The use of metallic alloy layers of high melting temperature is also possible and is being considered.